Results of the ²⁴⁴Cm, ²⁴⁶Cm and ²⁴⁸Cm neutron-induced capture cross sections measurements at EAR1 and EAR2 of the n_TOF facility

Abstract

Accurate neutron capture cross section data for minor actinides (MAs) are required to estimate theproduction and transmutation rates of MAs in light water reactors, critical fast reactors like Gen-IV systems, and other innovative reactor systems such as accelerator driven systems (ADS). In particular, ²⁴⁴Cm, ²⁴⁶Cm and ²⁴⁸Cm play a role in the transport, storage and transmutation of the nuclear waste of the current nuclear reactors, due to the contribution of these isotopes to the radiotoxicity, neutron emission, and decay heat in the spent nuclear fuel. Also, capture reactions in these Cm isotopes open the path for the formation of heavier elements. In this work, the results of the capture cross section measurement on ²⁴⁴Cm, ²⁴⁶Cm and ²⁴⁸Cm performed at the CERN n_TOF facility are presented. It is important to notice that the Cm samples used in the experiment at n_TOF have been used previously in an experiment at J-PARC, this experiment and the previous one done in the 70s with a nuclear explosion were the only previous capture experiments for these isotopes. At n_TOF, the capture cross section measurements of ²⁴⁴Cm, ²⁴⁶Cm and ²⁴⁸Cm were performed at the 20 m vertical flight path (EAR2) with three C₆D₆ total energy detectors. In addition, the cross section of ²⁴⁴Cm was measured at the 185 m flight path (EAR1) with a Total Absorption Calorimeter (TAC). The combination of measurements in EAR1 and EAR2 has contributed to controlling and reducing the systematic uncertainties in the results. The compatibility of the different measurements performed and the techniques to obtain the results are presented in this paper as well as the procedure to obtain the resonance parameters.